Bentonite: how should hydrated slurry be stored?

[theracles]

Having made up a slurry of Bentonite using hot/boiling water, after much "Squidging and interminable hours of shaking in a jam jar, I had enough prepared to "dose" my first Demijohn.
I was not impressed with the result after carefully stirring it into the must, the majority immediately sunk to the bottom seemingly having achieved nothing!

I had 4 more Demijohns of Ginger wine awaiting similar treatment, for which the remaining slurry was destined, however since the wait for some encouraging signs from the initial batch has taken some 4 weeks, I'm now unsure if I should use the prepared slurry as it has been stored at room temperature in the tightly sealed jam jar.

Will it be safe to use?
I can find no advice online on how to store the slurry once prepared but not used.
Grateful for any advice.

 

[bernardsmith]

Great question, theracles. I have always assumed that bentonite is an inorganic mineral clay and as such would not harbor bacteria and spoil over time. I have kept the prepared clay in capped containers for many months and have never found any problem when I applied the fining agent.

But I am a little surprised that the quantity you added immediately sank. I very , very rarely make wine kits but most kit manufacturers today suggest that you add the clay very soon after pitching the yeast and the action of the production of CO2 by the yeast should continually force the bentonite back towards the surface even as it drops towards the bottom after latching onto proteins and other particles so that it is being constantly rising and falling. Is it possible that when you dropped the bentonite into the must it was just too thick? I don't shake my water bentonite solution. I use my blender... Far more energy applied to mixing with far less effort and always with far better results...

 

[theracles]

Thanks for replying bernardsmith.
Have to clarify that like you, I don't make "Kit" wines, mine are usually foraged fruit but this time I wanted to make a spicy Ginger wine to keep me in Whisky Mac's during the winter!
From the taste of it and the ABV ranging from 16.3% through to 17.12%, I might just dispense with the Whisky!

I have to admit my only recollection of Bentonite was whilst working in Dubai where the oil drilling industry just referred to as "mud" but in vast quantities!
I am satisfied that the mix was "slack" enough, it has the consistency of thin cream, maybe a little more runny.

The initial two tablespoon dose was administered to a one litre Demijohn of red wine which I "found" lurking under the stairs!
It was a total surprise and could not be less than 10, maybe even 15 years old and was either Blackberry or Elderberry!!
Having tasted it and decided to back sweeten it, I was dismayed to find that it began to ferment again.
I quickly stopped that, racked it off, degassed and stabilised with sorbate and Kmet, but it was cloudy so I decided to experiment with the Bentonite prior to using it in earnest on my current Ginger Wine.

As I described, despite a good stirring, most of the two tablespoons of slurry formed a grainy grey deposit after just a couple of hours.
It was almost two weeks before I could actually see an improvement and now after 4 weeks, it is evident that there was more Bentonite in suspension than I had thought.
The initial grainy grey deposit was may be 2mm deep and this has now morphed into a fine silt with a depth of about 6mm and the wine whilst not perfect has a much greater clarity.
Job done, I think, though I've not yet tasted it. To be fair if it doesn't induce vomiting then that one is a win!

I'm encouraged by your own experience in just keeping the prepared Bentonite slurry in a sealed container.
I'm thinking that I might microwave the jam jar (without the lid) to sterilise the content before using it once cooled.
None of this can currently take place since I have no way of cooling the wine, current ambient is 27ºC

 

[theracles]

Just found this which is the only thing on the internet I have found regarding the storage of Bentonite, I think Page two refers to "Dry" Bentonite whilst Page three advises against storing slurry for more than a few hours!
Might just mix some more when this heat dies down!

 

[Maylar]

I've only used it dry (powdered) at 1 TSP per gallon a day or 2 after pitching yeast. Gotta leave headroom for the foam that will ensue.

 

[bernardsmith]

But given the amount of bentonite you added and the amount of sediment that formed there is no relationship between the bentonite and the sediment other than the bentonite MUST be pulling out of solution all kinds of particulates. In a 1 gallon carboy 6 mm of sediment on the floor is considerably more than the two teaspoons of clay AND water that you added.

 

[theracles]

I have to agree Bernard; and to further underline the point, I only used two tablespoons of the mixed slurry.
The full amount mixed was two teaspoons of powder with 4fl.oz (or 8 tablespoons) of water, so the resultant sediment produced in my must was down to the equivalent of half a teaspoon of powder mixed in just two tablespoons of water!

The almost immediate appearance of what I considered to be a significant deposit led me to believe that despite stirring, the slurry had just sunk!

The majority of clearing has happened over the last three weeks, and has indeed surprised me and restored my faith in Bentonite!

Given the advice from the Perdue University (above) I recon that once the weather cools, I'll mix a fresh batch rather than chance using that which was left over!